Swinging doors are commonly used at the entrances of most public buildings, shopping malls, department stores, business buildings and the like. Such swinging doors are typically configured to open inwardly into the particular building or outwardly from the building and comprise two adjacent door members, generally made from glass, wool, steel and the like, that are pivotally mounted at top and bottom portions of non-adjacent ends to supporting members in the floor and in an upper portion of a door frame, respectively. The doors, when placed in the closed position, are positioned adjacent one another about adjacent ends opposite to the pivotally attached ends. Accordingly, both doors are opened by pushing a handle or rail positioned near each adjacent end, causing the adjacent ends of each door to move outwardly and away from one another in a pivoting manner.
The doors are configured to both open in response to a predetermined amount of force imparted to the hand rail, and close in a controlled manner by use of a door closer attached to the nonadjacent ends of each door at each door bottom via a pivot arm. The pivot arm is attached within the closer to a spring mechanism that controls the amount of resistance needed to open the door. Once the door is opened, the door is returned to its closed position by the return action of the spring mechanism that is hydraulically dampened to prevent the door from slamming shut.
The door closure is configured at the factory and installed into buildings with the spring tension of the spring mechanism set to a predetermined amount. As temperature outside of a building changes, due to the changing seasons, so does the internal heating and cooling of the building. In large buildings, the amount or volumetric flow rate of cool air needed to provide a comfortable indoor temperature during the hot summer months often results in the creation of a positive pressure differential between indoor and outdoor environment, i.e, the pressure inside the building is greater than the atmospheric pressure outside the building. This additional indoor pressure imparts a sufficient pressure force against the doors to cause the doors to open a small amount defined by the equilibrium point between the pressure force of the air inside the building and the spring force imposed by the door closer.
Accordingly, to accommodate the positive pressure created by a building's cooling system within a building during the Summer months the spring tension on the door closer must be adjusted from its preset amount, i.e., tightened, to overcome such positive pressure. It is typically easier to heat the inside of a building than cool the same building. Therefore, during the Winter months the problem of positive pressure within the building does not exist, rather, the spring tension of the door closer must be adjusted, i.e., loosened, from its Summer position back to the preset condition so that the opening of the doors is not overly difficult.
Recent passage of the American Disabilities Act also imposes limitations on the amount of force that is required to open such swinging doors installed in public and private buildings. Under the Act, the amount of force needed to open such doors must not be overbearing so as to facilitate operation of the door by people with a disability or by senior citizens. Although no firm number has been provided, it is believed that in order to meet the criteria under the Act the spring tension for the door closers will need to be adjusted to about 81/2 pounds. The spring tension of the door closing mechanism preset at the factory and installed in existing buildings is approximately 101/2 pounds. Therefore, in order to comply with the Act the spring mechanism in door closers in all public and private buildings must either be adjusted, i.e., loosened, or be replaced with new lower spring tension door closers, an option that is not economically desirable.
The door closer does not comprise a simple adjustment mechanism, thus, the act of adjusting the spring mechanism is a complex operation requiring the removal of both doors, the removal of a threshold member extending along the floor covering the door closers, and the removal of the door closers from their position mounted within the floor. The doors closers are then either returned to the factory or taken to a machine shop where the door closer can be secured in a vice while a spring cover is loosened and adjusted to either relieve or increase the spring tension of the spring within. Once adjusted, the door closers are replaced and the doors are reassembled. Accordingly, this method of adjusting the spring mechanism in a door closer is difficult to implement, time consuming, inconvenient, and costly. Also, during the adjustment process the unassembled condition of the doors are potentially dangerous and unsightly to people visiting the building.
It is, therefore, desirable that a device be provided to facilitate the adjustment of spring tension within a door closer without the need to remove the door closer from its floor mounted position. It is desirable that the device be configured in a manner accommodating simple operation by use of conventional hand tools. It is also desirable that the device be economical to manufacture and, thus be constructed using both conventional manufacturing techniques and conventional building materials.